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Re: Issue: Synch/Asynch Web services

From: Sai Surya Kiran Evani <evani@informatik.uni-freiburg.de>
Date: Mon, 11 Aug 2003 10:21:33 +0200
Message-ID: <3F37520D.8090904@informatik.uni-freiburg.de>
To: "Cutler, Roger (RogerCutler)" <RogerCutler@chevrontexaco.com>
CC: www-ws-arch@w3.org
Hi,

What I meant was that each WSDL port could be thought of as a queue and 
a service which communicates using these ports as a process.

The two important theories dealing with communicating processes - 
Communicating Sequential processes(Hoare), Calculus of Communicating 
Systems(Pi-Calculus etc - Robin Milner) assume that message passing is 
immediate or based on bounded length queues.

On the other hand, communication among processes with unbounded FIFO 
queues has been studied using an abstraction called "Network of 
Communicating Finite State Machines" to my knowledge.

-Kiran.

Cutler, Roger (RogerCutler) wrote:

>I would personally appreciate it if you would explain this a little more
>fully.
>
>-----Original Message-----
>From: Sai Surya Kiran Evani [mailto:evani@informatik.uni-freiburg.de] 
>Sent: Saturday, August 09, 2003 10:44 AM
>To: www-ws-arch@w3.org
>Subject: Re: Issue: Synch/Asynch Web services
>
>
>
>Hi,
>
>Just curious if there would be anything defined regarding the queueing 
>behaviour of a web service. I guess the analysis of the systems involved
>
>- the provider or the invoker would be different in the cases of 
>unbounded queues and bounded queues..
>
>Thanks,
>Kiran.
>
>
>Geoff Arnold wrote:
>
>>>Bottom line: From my point of view async/sync is a question of 
>>>blocking or not, and completely separated from the underlying 
>>>protocol. It just has to provide sufficient ways to handle the 
>>>message exchange in the way desired by the application.
>>>
>>If it were the case that sync/async were merely a question of blocking
>>
>
>>or non-blocking, WSA (and SOAP, and.....) would have nothing to say on
>>
>
>>the subject, since our specifications are silent on the question of 
>>implementation.
>>
>>However there is an alternative viewpoint (that sync/async is a 
>>property of message exchange patterns), and this has nothing 
>>whatsoever to do with implementation, blocking, threading and so 
>>forth.
>>
>>Geoff
>>
>
>
>
>
>
Received on Monday, 11 August 2003 04:21:49 GMT

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